Add support for MODE_VECTOR_BOOL

This patch adds a new mode class to represent vectors of booleans.
GET_MODE_BITSIZE (m) / GET_MODE_NUNITS (m) determines the number
of bits that are used to represent each boolean; this can be 1
for a fully-packed representation or greater than 1 for an unpacked
representation.  In the latter case, the value of bits other than
the lowest is not significant.

These are used by the SVE port to represent predicates.

2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* mode-classes.def (MODE_VECTOR_BOOL): New mode class.
	* machmode.h (INTEGRAL_MODE_P, VECTOR_MODE_P): Return true
	for MODE_VECTOR_BOOL.
	* machmode.def (VECTOR_BOOL_MODE): Document.
	* genmodes.c (VECTOR_BOOL_MODE): New macro.
	(make_vector_bool_mode): New function.
	(complete_mode, emit_mode_wider, emit_mode_adjustments): Handle
	MODE_VECTOR_BOOL.
	* lto-streamer-in.c (lto_input_mode_table): Likewise.
	* rtx-vector-builder.c (rtx_vector_builder::find_cached_value):
	Likewise.
	* stor-layout.c (int_mode_for_mode): Likewise.
	* tree.c (build_vector_type_for_mode): Likewise.
	* varasm.c (output_constant_pool_2): Likewise.
	* emit-rtl.c (init_emit_once): Make sure that CONST1_RTX (BImode) and
	CONSTM1_RTX (BImode) are the same thing.  Initialize const_tiny_rtx
	for MODE_VECTOR_BOOL.
	* expr.c (expand_expr_real_1): Use VECTOR_MODE_P instead of a list
	of mode class checks.
	* tree-vect-generic.c (expand_vector_operation): Use VECTOR_MODE_P
	instead of a list of mode class checks.
	(expand_vector_scalar_condition): Likewise.
	(type_for_widest_vector_mode): Handle BImode as an inner mode.

gcc/c-family/
	* c-common.c (c_common_type_for_mode): Handle MODE_VECTOR_BOOL.

gcc/fortran/
	* trans-types.c (gfc_type_for_mode): Handle MODE_VECTOR_BOOL.

gcc/go/
	* go-lang.c (go_langhook_type_for_mode): Handle MODE_VECTOR_BOOL.

gcc/lto/
	* lto-lang.c (lto_type_for_mode): Handle MODE_VECTOR_BOOL.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r256202

1 files changed, 37 insertions, 1 deletions

diff --git a/gcc/genmodes.c b/gcc/genmodes.c
index b134c1b..9e37d65 100644
--- a/gcc/genmodes.c
+++ b/gcc/genmodes.c
@@ -375,6 +375,10 @@ complete_mode (struct mode_data *m)
       m->bytesize = 2 * m->component->bytesize;
       break;
 
+    case MODE_VECTOR_BOOL:
+      validate_mode (m, UNSET, SET, SET, SET, UNSET);
+      break;
+
     case MODE_VECTOR_INT:
     case MODE_VECTOR_FLOAT:
     case MODE_VECTOR_FRACT:
@@ -526,6 +530,28 @@ make_vector_modes (enum mode_class cl, unsigned int width,
     }
 }
 
+/* Create a vector of booleans called NAME with COUNT elements and
+   BYTESIZE bytes in total.  */
+#define VECTOR_BOOL_MODE(NAME, COUNT, BYTESIZE) \
+  make_vector_bool_mode (#NAME, COUNT, BYTESIZE, __FILE__, __LINE__)
+static void ATTRIBUTE_UNUSED
+make_vector_bool_mode (const char *name, unsigned int count,
+		       unsigned int bytesize, const char *file,
+		       unsigned int line)
+{
+  struct mode_data *m = find_mode ("BI");
+  if (!m)
+    {
+      error ("%s:%d: no mode \"BI\"", file, line);
+      return;
+    }
+
+  struct mode_data *v = new_mode (MODE_VECTOR_BOOL, name, file, line);
+  v->component = m;
+  v->ncomponents = count;
+  v->bytesize = bytesize;
+}
+
 /* Input.  */
 
 #define _SPECIAL_MODE(C, N) \
@@ -1438,7 +1464,8 @@ emit_mode_wider (void)
 
 	  /* For vectors we want twice the number of components,
 	     with the same element type.  */
-	  if (m->cl == MODE_VECTOR_INT
+	  if (m->cl == MODE_VECTOR_BOOL
+	      || m->cl == MODE_VECTOR_INT
 	      || m->cl == MODE_VECTOR_FLOAT
 	      || m->cl == MODE_VECTOR_FRACT
 	      || m->cl == MODE_VECTOR_UFRACT
@@ -1657,6 +1684,7 @@ emit_mode_adjustments (void)
       printf ("\n  /* %s:%d */\n", a->file, a->line);
       switch (a->mode->cl)
 	{
+	case MODE_VECTOR_BOOL:
 	case MODE_VECTOR_INT:
 	case MODE_VECTOR_FLOAT:
 	case MODE_VECTOR_FRACT:
@@ -1688,6 +1716,10 @@ emit_mode_adjustments (void)
 		      m->name);
 	      break;
 
+	    case MODE_VECTOR_BOOL:
+	      /* Changes to BImode should not affect vector booleans.  */
+	      break;
+
 	    case MODE_VECTOR_INT:
 	    case MODE_VECTOR_FLOAT:
 	    case MODE_VECTOR_FRACT:
@@ -1728,6 +1760,10 @@ emit_mode_adjustments (void)
 	      printf ("  mode_base_align[E_%smode] = s;\n", m->name);
 	      break;
 
+	    case MODE_VECTOR_BOOL:
+	      /* Changes to BImode should not affect vector booleans.  */
+	      break;
+
 	    case MODE_VECTOR_INT:
 	    case MODE_VECTOR_FLOAT:
 	    case MODE_VECTOR_FRACT: